In the belt-tightening theme, “the nation is a family that has outspent its income and is trying to get back in control,” Shiller writes. “It’s a powerful thought, because we know that mismanagement of household finances can lead to a family’s ruin.”

But if everyone tightens their belt at once, the economy weakens, he says.

“When that happens, some collective action — government stimulus — is needed.”

As for “winter on the family farm,” it entails keeping busy despite the lack of planting and harvesting, Shiller says. “We should demand that everyone help out with long-term projects on the farm, like fixing the barn or digging a well.”

That means higher government spending to stimulate the economy matched by higher taxes to pay for it, Shiller says.

He may feel more confident in his view given a recent report from Fitch Ratings and Oxford Economics concluding that stimulative fiscal and monetary policies added more than 4 percentage points to U.S. GDP in 2010 and 2011 combined, keeping the economy out of recession.